Boiler



y 1, 1933. A. M. ROSSMAN ET AL 1,917,275

' BOILER Original Filed Feb. 24, 1927 5 Sheets-Sheet l INVENTOR mm 02044441 1- flfi'w -Zlzdam ATTORNEY5 July 11, 1933.

A. M. ROSSM'AN ET AL BOILER Original Filed Feb. 24, 1927 5 Sheets-Sheet 2 pr/111111,, I /I 01,

ATTORNEYS July 11, 1933. A. M ROSSMAN ET AL 1,917,275

BOILER Original Filed Feb. 24, 1927 5 Sheets-Sheet 3 NVENTORS h MM J wig" 643w W r JM ATTORNEYJ July 11, 1933. M RQSSMAN ET AL 1,917,275

BOILER Original Filed Feb. 24, 1927 5 Sheets-Sheet 4 July 11, 1933. A. M. ROSSMAN El AL BOILER Original Filed Feb. 24, 1927 5 Sheets-Sheet 5 M k2 INVENTORS g i/zaflm *MTTQRN EYS Patented July 11, 1933 UNITED STATES PATENT OFFICE ALLEN M. RUSSIAN AND HERMAN O. HEATON, OF CHICAGO, ILLINOIS BOILER Application filed February 24, 1927, Serial No. 170,488. Renewed March 13, 1931.

This invention relates to steam generators or boilers. It is especially useful for burning powdered fuel, though it is not restricted to any particular sort of fuel, as gas, oil, etc., may be used. The invention will be understood from the description in connection with the accompanying drawings, in which Fig. 1 is a vertical section through an illustrative embodiment of the invention taken along the line 11 of Fig. 2; Fig. 2 is a section along the line 22 of Fig. 1; Fig. 3 is a section along the line 3-3 of Fig. 1; Fig; 4 is a vertical section through a modification; Fig. 5 is a section along the line 55 of Fig. 4; Fig. 6 is a section along the line 66 of Fig. 4.; Fig. 7 is a section along the line 77 of Fig. 4; Fig. 8 is a vertical section through another'modification; Fig. 9 is a section along the line 99 of Fig. 8; Fig. 10 is a section along the line 10-10 of Fig. 1 on an enlarged scale; Fig. 11 is a section along the line l1-11 of Fig. 1 on an enlarged scale, and Fig. 12 is a longitudinal section through a steam andwater separator.

In the drawings reference character 1 indicates vertically disposed tubes that are preferably arranged in one or more circular rows, two such rows being shown in Figs. 1, 2 and 3. These tubes are installed so as to lie close together along their intermediate portions and the upper and the lower ends of these tubes as shown at 1" and 1", are bent outwardly to form cones, thus causing the ends of the tubes to diverge from each other, leaving V-shaped spacesbetween them and enabling them to be expanded into headers along straight rows of holes without destroying the ligament strength of the headers to too great an extent. The upper and lower torus shaped headers are shown at 2 and 3, respectively, into which the ends of the tubes 1 are expanded. Reference character 4. indicates rows of tubes that may also be arranged in circular rows spaced from the tubes 1 but lying close together along their intermediate parts to form a furnace wall. Two circular rows of tubes4are shown in Fig. 1 and the upper ends of alternate tubes of the inner row of tubes 4 are offset at short distances inwardly and outwardly and the up,

per ends of the outer row of tubes 4. are offset outwardly with alternate ones offset o tering the header 2 with suflicient space between the tubes to permit passage of the products of combustion. The lower portion of the tubes 4 is bent outwardly as shown at 4", to form a cone with all of the tubes at the base of the cone lying along the circumference of a single circle. The tubes 4: extend downwardly from the base of the cone to form a cylindrical body, as shown at 4., the extreme lower ends of alternate tubes on the cylindrical portion being olfset inwardly to have two rows of tubes entering the header 3 to preserve the ligament strength of the header. Some of the tubes on the cylindrical portion/1 bend to the side as shown at 4 to form spaces through which fuel burners 5 may extend, these fuel burners being arranged to project the fuel into the enlarged lower portion of the furnace in tangential directions. A conically shaped ash pit 6 extends downwardly from the header 3 and the spaced portions 1" of the tubes 1 operate as a slag screen between the furnace and the ash pit. Refractory material such as tile is installed at the outside of the tubes 4 so as to make a gas-tight wall 7 and extends from the header 3 upwardly to the lower ends of the portions of the tubes 4. A roof 8 of refractory material extends across the circular space within the header 2, thence below the header and outwardly a short distance, thence downwardly as shown at 9 to provide a cylindrical wall that terminates approximately on a level with the upper ends of the portions 4" of the tubes 4. A casing 10 on 90 the outside of the cylindrical wall 9 is extended upwardly a distance above the roof f the furnace. A casing 11, preferably cylindrical in shape and concentric with the casing 10, extends upwardly some distance 5 above the roof 8 and is provided with insulating material 12 on the outside thereof. Tubes 15 extend from the upper header 2 to steam and water separators 16 that are located between the walls 9 and 12. A portion of one of the separators 16 is shown more in detail in Fig. 12. As many of these tubes and separators 16 may be provided as are desirable, two being shown in this illustrative embodiment of the invention. Pipes 17 lead from the steam spaces of the separators 16 to a superheater to be described below. Pipes 18 lead from the water spaces of these separators 16 to the lower header 3. A feed water inlet pipe 19 extends into each separator 16 to near the bottom thereof, and the lower end thereof is open, and the lower portion is perforated and is surrounded by a sleeve 19' spaced a short distance from the pipe 19 to provide an annular space around the same, the lower end of the sleeve 19' being open, and the space between the upper end thereof and the outside of the pipe 19 being provided with openings 19".

The superheater comprises arcuate shaped tubes 20 that are horizontally disposed between the walls 7 and 9 and are expanded into headers 21 and 22 that are radially disposed in the space between the walls 7 and 9. The headers 21 and 22 are superposed and may be so connected that the steam flows in parallel paths through the tubes 20, or they may be so connected that the steam flows in series through the tubes. In each case the :steam would enter the lowermost header of the row of inlet headers and would be discharged through the pipes 23 to the steam main from the uppermost header of the row of outlet headers, so as to procure counter current flow of steam through the tubes with respect to hot gases passing over the tubes.

An economizer or feed water heater comprises circular tubes 25 similar to tubes 20 of the superheater that are also located b'etweenthe walls 7 and 9 and enter radially disposed horizontal headers 26and 27 that maybe connected as above described in connection with the superheater, so as to obtain either parallel or series flow of the Water through the headers in counter current direction with respect to hot gases.

Air heaters 28 (Figs. 2 and 10) are installed in the annular space between the casings 10 and 11 on opposite sides of the drums 16. They comprise alternate compartments 29 and 30 arranged side by side for air and 7 gas, respectively, which are caused to flow in opposite directions, so'that heat will be imparted from the hot waste gases to the cold air that is to be used for combustion purposes without mixing the gases and the air. These air heaters may, however, be ofdifi'erent well known types in which air for combustion purposes is heated by the waste products of" combustion from the furnace.

A motor 31 is installed above the boiler and a vertical shaft 32 therefrom drives a forced draft fan 33 and an induced draft fan 34. Ducts 35 discharge cold air from the exhaust side of the forced draft fan 33 into an annular chamber 35' from which the air enters the air inlet side of the air heater 28 and an annular spaced air chamber 36 connects with the air exhaust sides or hot air sides of the air heaters 28. Conduits 37 lead from the hot air chamber 36 to the fuel burners 5. Conduits 38 lead from the waste or coal gas outlet side of the air heaters 28 to the inlet of the induced draft fan 34 and a passage 39 leads from the exhaust side of the fan 34 to the stack.

The operation is as follows: Feed water enters the lower part of the economizers 25 and passes from the upper part of the same through'pipes 19 to the lower parts of the separators 16, the water level being kept slightly below the upper header 2. Fuel through the burners 5 and hot air through the conduits 37 are introduced tangentially into the lower enlarged portion of the furnace between the tubes 1 and 4, the ashes or slag forming material falling downwardly into contact with the portion 1" of the water filled tubes that chill the same and prevent slag from forming on the tubes, thus permitting the ashes to pass into the ashpit 6. Combustion takes place between tubes 1 and 4: and the hot products rise in spiral paths and pass somewhat radially outwards through the spaces between the upper portions 4' of the tubes 4, thence downwardly between the -walls 7 and 9 over the tubes 20 of the superheater, and the tubes 25 of the economizer or feed water heaters, thence under the edges of the wall 9 upwardly through the compartments 30 of the air heaters 28, thence through the conduits 38 and the fan 34 into the stack. At the same time cool air enters the fan 33 and passes through the conduits 35 into the annular chamber 35 thence downwardly through the compartments 29 of air heaters 28 in a counter current direction with respect to the waste products of combustion into the annular chamber 36 thence through the conduits 37 into the furnace.

In the modification shown in Figs. 4 to 7 similar parts are designated by the same reference characters with the subscript 4, so it is not believed to be necessary to describe all of the parts in detail again in order to understand this modification.

" This modification is adapted to cause the products of combustion to pass downwardly. and then upwardl instead of passing first intermediate portions and alternate tubes are til ofi'set inwardly for short distances from the ends of the tubes, thus providing spaces between these portions of the tubes and also providing two rows. of tubes where they enter the headers 2 and 3 to preserve ligament strength.

in this modification the separators 16 are shown as extending from a short distance above the header 2.; to slightly below the level of the header 3, and these drums are housed in enclosures 19 between the walls 7 4 and 12,. The superheater 20 is installed in the lower portion of the annular space between the walls? and 12,, the water heater 25,, is installed above the superheater and the air heaters :28 are installed above the econoniizer. The hot air is conducted from the hot air chamber 36 into the upper portions of the furnace between the tubes 1 and 4. alongside the fuel burners 5,. The operation is similar to that described in connection with Fig. 1, except that the hot products of combustion pass downwardly in somewhat spiral paths, finally passing through spaces between the portion 1 of the tubes 1 thence outwardly somewhat radially through the spaces between the portions of the tubes 1 and 4' thence upwardly into contactwith the superheater tubes, economizer tubes, and thence through the air heater and induced draft fan to the stack.

The modification shown in Figs. 8" and 9 is similar to that shown in Figs. at to 7 in that the hot products of combustion pass first; downwardly thence upwardly. The parts in this modification that are similar to parts in the other modification are designated by the same reference characters with the subscript 8 and it is, therefore, not necessary to describe the same again in detail. The inner rows of tubes 1 have their upper and lower ends extending outwardly similar to Fig. 4, but their lower portions are disposed as elements of a cone, there being two rows near the vertex as shown at 1" and a single row near the base of the cone as shown at 1' The outer row of tubes 4 have their lower ends extending outwardly as shown at i along the surfaces of two cones, thus providing spaces between the tubes for the passage of the hot products of combustion. in this modification the wall 9 is extended vertically above the roof 8 and the lower end of the space between the walls 7 and 9 is closed, thus forming ,a closed annular box in which the fuel burners 5, are located. Fire observation openings 40,, may be provided in the wall 9 Hot air from the conduit 36 passes directly into the space between the walls 7 and 9 through the openings 36' The operation is similar to that described in connection with Fig. 4. The hot products of combustion pass downwardly in somewhat spiral paths between the tubes 1 and 4 through the spaces between the portions 1' thence upwardly through the space between the portions 1' and 4 thence into contact with the superheater, the economizer and through the air heater 28 and the fan 34 to the stack.

in this invention the furnace of the boiler is preferably made circular in cross section and the walls thereof are completely lined by steam making tubes and a circular row of steam making tubes is located along the middle portion of the furnace. The flow is upwardly in all of the steam making tubes and the mixture of steam and water is discharged into separators so that separation of steam and water is obtained. The water flows downwardly from the separators at the outside of the furnace to the lower header from which it enters the lower ends of the steam making tubes. The superheater and the economizer tubes are arcuate shaped and are disposed so as to absorb a large portion of heat from the gases, and the flow of water and steam is counter current with respect to the gases. The arcuate shape of the tubes gives ample provision for expansion and contraction and at the same time access to the tubes can be obtained for cleaning them.

Heat losses by radiation are minimized andv the installation is very economical of space. There is also room for the installation of a dust collector between. the air heater and the induced draft tan in case it is needed.

We claim:

. i. in a boiler, an inner row of tubes surrounding a central space, an outer row of tubes surrounding said first named row and spaced therefrom did'erent distances at difierent points, a header to which one end of.

tubes in both rows are connected anda difierent header to which the other ends of said tubes are connected, and means for introducing fuel between said rows of tubes and guiding it between said rows.

2. In a boiler, an inner group of tubes, an outer group of tubes spaced therefrom, a header to which one end of said tubes are connected and a header to which the other ends of said tubes are connected, and means for introducing fuel into the space between said groups of tubes and guiding it between said groups.

3. In a boiler, an inner circular row of tubes, an outer circular row of tubes spaced- Kill) 6. Ina boiler, an economizer comprising arcuateshaped tubes, a superheater comprisin arcuate shaped tubes, a plurality of said tubes when placed end to end forming substantially a complete circle, an annularly shaped gas conduit in which said economizer and superheater are located, a circulary shaped air heater located outside of said economizer and superheater, and an annularly shaped gas conduit of larger diameter than the said first named one in which said air heater is located.

7. In a boiler, a row of upwardly extending steam generating tubes, a circularly shaped air heater around said tubes, said heater being in sections spaced apart, and a vertically disposed steam and water separator located in a space between said sections and connected to said steam generating tubes.

8. In a boiler, steam generating tubes, economizer tubes, superheater tubes, an air heater around said tubes, said air heater being formed so as to leave a space between portions thereof, and a vertically disposed steam and water separator located in said space and connected to said economizer tubes and said steam generating tubes.

ALLEN M. ROSSMAN. HERMAN C. HEATON. 

